SocialPub/PrivaPub.Tests/Federation/ParticipationTests.cs

using MongoDB.Entities;

using PrivaPub.Models.Post;
using PrivaPub.Models.Social;
using PrivaPub.Tests.Support;

using System.Text.Json.Nodes;

using static PrivaPub.Tests.Support.FederatedSeeds;

namespace PrivaPub.Tests.Federation
{
	// a persona joins a remote event (owner decision 2026-10-05): Join, answered Accept or Reject; Leave
	[Trait("Category", "Integration")]
	public sealed class ParticipationTests : IAsyncLifetime
	{
		Harness _harness;

		public async ValueTask InitializeAsync()
		{
			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
			_harness = await Harness.Start();
		}

		public async ValueTask DisposeAsync()
		{
			if (_harness != default)
				await _harness.DisposeAsync();
		}

		async Task<(PrivaPub.Federation.Actors.LocalActor Alice, RemoteActor Group, Post Event)> Announced(string joinMode = "free")
		{
			var token = TestContext.Current.CancellationToken;
			var (_, alice) = await _harness.Persona("alice");
			var group = new RemoteActor(_harness.Peer, "group", type: "Group");
			await Follows(alice.Id, group);
			var happening = new JsonObject
			{
				["id"] = NewId(group, "events"), ["type"] = "Event", ["name"] = "A picnic", ["content"] = "<p>bring bread</p>",
				["attributedTo"] = group.Id, ["startTime"] = DateTime.UtcNow.AddDays(3).ToString("O"), ["joinMode"] = joinMode,
				["to"] = new JsonArray(PrivaPub.Federation.Objects.Addressing.Public), ["cc"] = new JsonArray(group.Id + "/followers")
			};
			await _harness.Deliver(group, "/human-centipede", Create(group, happening));
			return (alice, group, await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(happening)).ExecuteSingleAsync(token));
		}

		Task<Participation> Of(PrivaPub.Federation.Actors.LocalActor alice, Post happening) =>
			DB.Default.Find<Participation>().Match(p => p.AvatarId == alice.Id && p.PostId == happening.ID).ExecuteFirstAsync(TestContext.Current.CancellationToken);

		[Fact]
		public async Task A_persona_joins_an_event_its_server_accepts_and_leaves_it()
		{
			var token = TestContext.Current.CancellationToken;
			var (alice, group, happening) = await Announced();

			Assert.True((await _harness.Participations.Join(alice, happening.ID, token)).Ok);

			var join = Assert.Single(await _harness.Outgoing(group.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Join");
			Assert.Equal((alice.Uri, happening.ObjectURI), (join["actor"]!.GetValue<string>(), join["object"]!.GetValue<string>()));
			Assert.Equal(ParticipationState.Pending, (await Of(alice, happening)).State);

			await _harness.Deliver(group, "/human-centipede", new JsonObject
			{
				["id"] = NewId(group, "accepts"), ["type"] = "Accept", ["actor"] = group.Id, ["object"] = join["id"]!.GetValue<string>()
			});
			Assert.Equal(ParticipationState.Accepted, (await Of(alice, happening)).State);

			Assert.True((await _harness.Participations.Leave(alice, happening.ID, token)).Ok);
			Assert.Null(await Of(alice, happening));
			var leave = Assert.Single(await _harness.Outgoing(group.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Leave");
			Assert.Equal(happening.ObjectURI, leave["object"]!.GetValue<string>());
		}

		[Fact]
		public async Task A_refusal_counts_an_answer_from_another_server_does_not_and_an_invitation_only_event_is_not_joined()
		{
			var token = TestContext.Current.CancellationToken;
			var (alice, group, happening) = await Announced();
			await _harness.Participations.Join(alice, happening.ID, token);
			var join = Assert.Single(await _harness.Outgoing(group.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Join");

			var stranger = new RemoteActor(_harness.Peer, "stranger", _harness.Peer.B);
			await _harness.Deliver(stranger, "/human-centipede", new JsonObject
			{
				["id"] = NewId(stranger, "accepts"), ["type"] = "Accept", ["actor"] = stranger.Id, ["object"] = join["id"]!.GetValue<string>()
			});
			Assert.Equal(ParticipationState.Pending, (await Of(alice, happening)).State);

			await _harness.Deliver(group, "/human-centipede", new JsonObject
			{
				["id"] = NewId(group, "rejects"), ["type"] = "Reject", ["actor"] = group.Id,
				["object"] = new JsonObject { ["id"] = join["id"]!.GetValue<string>(), ["type"] = "Join", ["actor"] = alice.Uri, ["object"] = happening.ObjectURI }
			});
			Assert.Equal(ParticipationState.Rejected, (await Of(alice, happening)).State);

			var (carol, _, invitationOnly) = await Announced("invite");
			Assert.Equal(422, (await _harness.Participations.Join(carol, invitationOnly.ID, token)).Status);
		}
	}
}